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From: Alexander Monakov <amonakov@ispras.ru>
To: qemu-devel@nongnu.org
Cc: Richard Henderson <richard.henderson@linaro.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Alexander Monakov <amonakov@ispras.ru>
Subject: [PATCH 5/5] Revert "meson: assume x86-64-v2 baseline ISA"
Date: Wed, 12 Jun 2024 13:55:25 +0300	[thread overview]
Message-ID: <20240612105525.8795-6-amonakov@ispras.ru> (raw)
In-Reply-To: <20240612105525.8795-1-amonakov@ispras.ru>

This reverts commit 294ac64e459aca023f43441651d860980c9784f1.

Reinstate the ability to use Qemu on x86 hosts that do not meet
x86_64-v2 ISA baseline.

Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
---
 meson.build | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/meson.build b/meson.build
index ec59effc..49962cce 100644
--- a/meson.build
+++ b/meson.build
@@ -336,13 +336,9 @@ if host_arch == 'i386' and not cc.links('''
   qemu_common_flags = ['-march=i486'] + qemu_common_flags
 endif
 
-# Assume x86-64-v2 (minus CMPXCHG16B for 32-bit code)
-if host_arch == 'i386'
-  qemu_common_flags = ['-mfpmath=sse'] + qemu_common_flags
-endif
-if host_arch in ['i386', 'x86_64']
-  qemu_common_flags = ['-mpopcnt', '-msse4.2'] + qemu_common_flags
-endif
+# ??? Only extremely old AMD cpus do not have cmpxchg16b.
+# If we truly care, we should simply detect this case at
+# runtime and generate the fallback to serial emulation.
 if host_arch == 'x86_64'
   qemu_common_flags = ['-mcx16'] + qemu_common_flags
 endif
-- 
2.32.0



  parent reply	other threads:[~2024-06-12 10:57 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-12 10:55 [PATCH 0/5] Reinstate ability to use Qemu on pre-SSE4.1 x86 hosts Alexander Monakov
2024-06-12 10:55 ` [PATCH 1/5] Revert "host/i386: assume presence of POPCNT" Alexander Monakov
2024-06-12 10:55 ` [PATCH 2/5] Revert "host/i386: assume presence of SSSE3" Alexander Monakov
2024-06-12 10:55 ` [PATCH 3/5] Revert "host/i386: assume presence of SSE2" Alexander Monakov
2024-06-12 10:55 ` [PATCH 4/5] Revert "host/i386: assume presence of CMOV" Alexander Monakov
2024-06-12 10:55 ` Alexander Monakov [this message]
2024-06-12 11:04 ` [PATCH 0/5] Reinstate ability to use Qemu on pre-SSE4.1 x86 hosts Daniel P. Berrangé
2024-06-12 11:12   ` Paolo Bonzini
2024-06-12 11:19     ` Alexander Monakov
2024-06-12 11:29       ` Paolo Bonzini
2024-06-12 11:46         ` Alexander Monakov
2024-06-12 11:58           ` Paolo Bonzini
2024-06-12 12:10             ` Alexander Monakov
2024-06-12 12:13               ` Paolo Bonzini
2024-06-12 13:34                 ` Alexander Monakov
2024-06-12 13:39                   ` Paolo Bonzini
2024-06-12 14:27                     ` Alexander Monakov
2024-06-12 11:38     ` Daniel P. Berrangé
2024-06-12 11:51       ` Paolo Bonzini
2024-06-12 12:21         ` Daniel P. Berrangé
2024-06-12 15:09           ` Daniel P. Berrangé
2024-06-12 15:29             ` Paolo Bonzini
2024-06-12 15:40             ` Alexander Monakov
2024-06-12 16:24               ` Daniel P. Berrangé
2024-06-12 17:06             ` Daniel P. Berrangé
2024-06-12 17:00         ` Daniel P. Berrangé
2024-06-12 17:08           ` Paolo Bonzini
2024-06-23 21:27     ` Alexander Monakov
2024-06-23 22:14       ` Richard Henderson
2024-06-12 11:14   ` Alexander Monakov

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